WO2015002379A1 - Battery pack protection device and method - Google Patents

Abstract

A battery pack protection device and method are disclosed. The battery pack protection device, according to the present invention, comprises: a sensing unit for sensing an overcharged state or an over-discharged state of a battery; a plurality of switches provided at a charging path and a discharging path of the battery; a control unit for controlling the switches so as to enable the battery to be both charged and discharged when the battery is not in the overcharged state or in the over-discharged state, and controlling the plurality of switches so as to allow only the discharging of the battery in the overcharged state thereof or to allow only the charging of the battery in the overdischarged state thereof according to an output signal of the sensing unit; and a display unit for displaying a charged state or a discharged state of the battery.

Description

Battery pack protection device and method

This application claims the benefit of the filing date of Korean Patent Application No. 10-2013-0077181 filed with the Korea Intellectual Property Office on July 2, 2013, the entire contents of which are incorporated herein.

The present invention relates to an apparatus and a method for protecting a battery, wherein the present invention detects an overcharge state or an overdischarge state of a battery and controls a plurality of switches installed in a charge path and a discharge path of the battery, thereby converting the charge and discharge of the battery into a current state. The present invention relates to a battery protection device and method that can smoothly adjust the charging and discharging time by allowing the user to easily know the current state of charge and discharge of the battery by smoothly extending the battery life.

With the rapid spread of electric and electronic devices due to the rapid development of the industry and the economy, uninterruptible power supply for stable power supply in case of power failure due to the increasing demand for stable power supply and demand for high quality power. The use of power supplies (UPS) is rapidly increasing. Degradation of power quality due to instantaneous blackouts, voltage sags and harmonics can cause significant economic losses for the industry. In order to solve this problem of power quality, UPS, which is used in many industries in the industry, has secured much reliability for stable operation due to the rapid development of power electronic technology, but power quality in case of power failure due to the failure of the battery for storing energy Degradation is often occurring.

Accordingly, the technology regarding a battery management system (BMS) for more efficient use and management of batteries is also increasing in importance. In particular, the BMS should be able to easily control the state of charge or discharge of the battery to prevent overcharge and overdischarge and protect the battery.

In general, a battery has a very high energy density, and when the battery is overcharged above a certain voltage, severely, the structure of the positive electrode active material collapses or the oxidation reaction of the electrolyte is accompanied, and if this continues, the voltage rises and the battery explodes or ignites. Done. In addition, the service life is shortened, and the battery's unstable characteristics pose a risk of an accident, causing a decrease in the overall reliability of the UPS.

Referring to FIG. 1, a conventional battery charge / discharge circuit is illustrated, which can control charge / discharge using only one switch 11 connected in series with a battery and a charge / discharge path. As a result, the conventional battery charge / discharge circuit prevents overcharge by opening the switch 11 to block the charging current when overcharge occurs. However, the discharge current was also unable to move due to the opening of the switch 11.

In the conventional battery charge / discharge circuit, when the overdischarge occurs, the switch 11 is opened to prevent the discharge current, thereby preventing the overdischarge. However, due to the opening of the switch 11, charging current was also impossible to enter.

As a result, the conventional method may require discharging even when overcharging and charging may be required even when overdischarging, and thus, the charging and discharging are prevented.

An object of the present invention relates to a battery protection device and method, which detects an overcharge state or an overdischarge state of a battery and controls conversion of charging and discharging of the battery by controlling a plurality of switches installed in the charge path and the discharge path of the battery. The present invention provides a battery protection device and method for smoothly adjusting to a current state and extending battery life, and allowing a user to easily know a current state of charge and discharge of a battery so that the charging and discharging time can be properly adjusted.

Battery protection apparatus according to an embodiment of the present invention, the sensing unit for detecting an overcharge state or an over discharge state of the battery; A plurality of switches provided in a charging path and a discharge path of the battery; And when the battery is not in an overcharge state or an overdischarge state, the switch controls the battery to allow both charging and discharging, and a plurality of switches to enable only discharge during overcharge or only charge during overdischarge by an output signal of the detector. It is configured to include a control unit for controlling.

The battery protection device may further include a plurality of unidirectional elements in a charge path and a discharge path of the battery.

The unidirectional device may be a diode.

The plurality of switches may include a first switch provided in the charging path and a second switch provided in the discharge path.

When the sensing unit detects an overcharge state, the controller may control the discharge to be possible by opening the first switch and closing the second switch.

When the detection unit detects an over-discharge state, the controller may close the first switch and open the second switch to control only charging.

The battery protection device may further include a display unit which displays a charged state or a discharged state of the battery.

The display unit may indicate that an overcharge state is detected when the detection unit detects an overcharge state and may display an over discharge state when the detection unit detects an overdischarge state.

Battery protection method according to an embodiment of the present invention, the step of detecting the overcharge or over-discharge of the battery; Controlling the plurality of switches to enable both charging and discharging of the battery when the battery is not in an overcharge state or an overdischarge state; And controlling the plurality of switches to enable only discharge upon overcharge or only charge upon overdischarge by the output signal of the sensing unit.

The controlling of the plurality of switches to enable only discharge upon overcharging or only charge upon overdischarge by the output signal of the sensing unit may include: detecting the overcharge state of the battery in the detecting step; By opening and closing the second switch can be controlled so that only the discharge.

The controlling of the plurality of switches to enable only discharge upon overcharging or only charge upon overdischarge by the output signal of the sensing unit may include: detecting the overdischarge state of the battery in the detecting step; The switch can be closed and the second switch can be opened to control only charging.

The battery protection method may further include displaying a charging state or a discharging state of the battery.

The displaying may include displaying an over discharge state when detecting an overcharge state in the detecting step, and displaying an over discharge state when detecting an over discharge state in the detecting step.

According to an aspect of the present invention, the present invention relates to a battery protection device and method, which detects an overcharge state or an overdischarge state of a battery and controls a plurality of switches installed in a charge path and a discharge path of the battery, thereby controlling charging and discharging of the battery. Provides battery protection devices and methods to smoothly adjust the current charging and discharging time by allowing users to easily know the current charging and discharging status of the battery by smoothing the conversion to the current state. can do.

1 is a circuit diagram illustrating a conventional battery charge / discharge device.

2 is a diagram schematically illustrating an electric vehicle to which a battery protection device according to an embodiment of the present invention may be applied.

3 is a block diagram schematically illustrating a configuration of a battery protection device according to an embodiment of the present invention.

4 is a circuit diagram showing an example of a specific configuration of a battery protection device according to an embodiment of the present invention.

5 is a flowchart illustrating a battery protection method according to an embodiment of the present invention.

The accompanying drawings of the present invention will be described in detail with reference to the following. Here, the repeated description, well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention, and detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art. Accordingly, the shape and size of elements in the drawings may be exaggerated for clarity.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless specifically stated otherwise.

In addition, the term "... unit" described in the specification means a unit for processing one or more functions or operations, which may be implemented in hardware or software or a combination of hardware and software.

The electric vehicle described below refers to a vehicle including one or more electric motors as propulsion force. The energy used to propel electric vehicles includes electrical sources such as rechargeable batteries and / or fuel cells. The electric vehicle may be a hybrid electric vehicle that uses a combustion engine as another power source.

2 is a view schematically showing an electric vehicle to which the battery protection device 100 according to an embodiment of the present invention may be applied.

2 illustrates an example in which the battery protection device 100 according to an embodiment of the present invention is applied to an electric vehicle, the battery protection device according to an embodiment of the present invention may be used for household or industrial energy storage system in addition to the electric vehicle. Any technical field may be applied as long as secondary batteries may be applied, such as an Energy Storage System (ESS) or an Uninterruptible Power Supply (UPS) system.

The electric vehicle 1 may include a battery 10, a battery management system (BMS) 20, an electronic control unit (ECU) 30, an inverter 40, and a motor 50.

The battery 10 is an electric energy source for driving the electric vehicle 1 by providing a driving force to the motor 50. The battery 10 may be charged or discharged by the inverter 40 according to the driving of the motor 50 and / or the internal combustion engine (not shown).

The type of the battery 10 is not particularly limited, and the battery 10 may be, for example, a lithium ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel hydrogen battery, a nickel zinc battery, or the like.

In addition, the battery 10 is formed of a battery pack in which a plurality of battery cells are connected in series and / or in parallel. In addition, one or more such battery packs may be provided to form the battery 10.

The BMS 20 estimates the state of the battery 10 and manages the battery 10 using the estimated state information. For example, the battery 10 state information such as state of charging (SOC), state of health (SOH), maximum input / output power allowance, and output voltage of the battery 10 is estimated and managed. In addition, the charging or discharging of the battery 10 is controlled using the state information, and the replacement time of the battery 10 may be estimated.

In addition, the BMS 20 may include a battery protection device 100 according to an embodiment of the present invention described below. By the battery protection device 100, the charging and discharging of the battery 10 may be more appropriately controlled, and the battery 10 may be protected during overcharging or overdischarging.

The ECU 30 is an electronic control device for controlling the state of the electric vehicle 1. For example, the torque degree is determined based on information such as an accelerator, a break, a speed, and the like, and the output of the motor 50 is controlled to match the torque information.

In addition, the ECU 30 transmits a control signal to the inverter 40 so that the battery 10 can be charged or discharged based on state information such as SOC and SOH of the battery 10 received by the BMS 20. .

The inverter 40 causes the battery 10 to be charged or discharged based on the control signal of the ECU 30.

The motor 50 drives the electric vehicle 1 based on the control information (for example, torque information) transmitted from the ECU 30 using the electric energy of the battery 10.

Since the electric vehicle 1 described above is driven by using the electric energy of the battery 10, it is important to accurately estimate the state of the battery 10, for example, a charged state, a discharge state, an overcharge state, and an overdischarge state. Do.

3 is a diagram illustrating a configuration of a battery protection device according to an embodiment of the present invention.

Referring to FIG. 3, the battery protection device 100 according to an exemplary embodiment of the present invention may include a detector 110, a switch 120, a controller 130, and a display 140. The battery protection device 100 shown in FIG. 3 is according to an embodiment, and its components are not limited to the embodiment shown in FIG. 3, and some components may be added, changed, or deleted as necessary. have.

The detector 110 detects an overcharge state or an overdischarge state of the battery 10. In one embodiment, the detection unit 110 may detect only when the charge amount or the discharge amount is more than or less than a predetermined reference value. For example, if the amount of charge flowing into the battery 10 is 100% or more, it may be determined as overcharge. Alternatively, when the discharge amount flowing into the battery 10 is 90% or more or the charge amount is 10% or less, it may be determined as overdischarge. The reference value may be a fixed value preset in the sensing unit 110 as an initial value, or may be a value that is changed by receiving a user input.

The switch 120 is a plurality of switches installed in the charging path and the discharge path of the battery 10. For example, the switch 120 may comprise one or more of a limit switch, a relay switch, a proximity switch, a micro switch, and a photoelectric switch.

The controller 130 controls the switch 120 to enable both charging and discharging of the battery 10, and controls the switch 120 to allow only charging or only discharging by the output signal of the sensing unit 110. can do. In one embodiment, when the sensing unit 110 detects an overcharge state, the controller 130 may control the discharge to be possible by opening the switch located on the charging path and closing the switch located on the discharge path. Alternatively, when the sensing unit 110 detects an over-discharge state, the controller 130 may close the switch located on the charging path and open the switch located on the discharge path to control only charging.

Hereinafter, a control method of the controller 130 of the battery protection device 100 according to an embodiment of the present invention will be described in detail with reference to FIG. 4.

4 is a circuit diagram showing an example of a specific configuration of a battery protection device 100 according to an embodiment of the present invention. Although the illustration of the controller 130 is omitted in FIG. 4, the controller 130 is actually connected to the switch 120 to control the switch 120. Referring to FIG. 4, in the battery protection device 100 according to an exemplary embodiment of the present invention, the switch 120 may include a first switch 121 installed in the charging path and a second switch 122 installed in the discharge path. have. In addition, the charging and discharging paths may further include a plurality of unidirectional elements 151 and 152. For example, the unidirectional elements 151 and 152 may be diodes.

Here, when not in the overcharged state or the overdischarged state, the controller 130 closes the first switch 121 installed in the charging path, and closes the second switch 122 provided in the discharge path, thereby allowing the movement of current to be free. Both charging and discharging are possible.

In the overcharge state, the controller 130 opens the first switch 121 installed in the charging path and closes the second switch 122 provided in the discharge path. Movement is limited and current is induced only in the discharge path.

Alternatively, in the over-discharge state, the control unit 130 closes the first switch 121 installed in the charging path, and when the second switch 122 installed in the discharge path is opened, the discharge path is formed by the unidirectional element. The movement of the current is limited and the current is induced only in the charging path.

3, the display unit 140 may display a charged state or a discharged state of the battery 10. For example, the display unit 140 may include a liquid crystal display (LCD) device, a light emitting diode (LED) device, a cathode-ray tube (CRT) device, a plasma display panel (PDP) device, and an organic light emitting diode (OLED) device. It may comprise one or more of.

Meanwhile, as long as the display unit 140 performs the above-described role, it is noted that the display unit 140 is not limited to the type of display device described above.

When the detection unit 110 detects an overcharge state, the display unit 140 may indicate that an overcharge state is detected, and when the detection unit 110 detects an overdischarge state, the display unit 140 may display an overdischarge state. The display unit 140 may select and display one or more charging / discharging states when the sensing unit 110 detects the sensing unit 110. For example, the voltage amount flowing into the battery 10, the charge amount, the discharge amount, the remaining amount, the charge / discharge state, or the current amount can be displayed.

5 is a flowchart illustrating a battery protection method according to an embodiment of the present invention.

Referring to FIG. 5, when the method for protecting a varistor according to an embodiment of the present invention is started, first, whether a battery is overcharged or overdischarged is detected (S11), and it is determined whether the battery is overcharged or overdischarged (S12). ). In the processes of steps S11 and S12, the description of the sensing unit 110 applies mutatis mutandis to the description thereof.

And when the battery does not detect the overcharge or overdischarge, it is possible to both charge and discharge the battery (S17). At this time, both the switch 121 (FIG. 4) and the switch 122 (FIG. 4) can be freely charged and discharged in a closed state.

When it is determined that the battery is overcharged, the first switch (Fig. 4 121) is opened and the second switch (122 in Fig. 4) is closed (S13), so that only the battery can be discharged (S15).

Alternatively, when it is determined that the battery is over discharged, the first switch (121 of FIG. 4) is closed and the second switch (122 of FIG. 4) is opened (S14) to allow only charging of the battery (S16). In the processes of steps S13 and S14, the description of the controller 130 is applied mutatis mutandis so that redundant description thereof will be omitted.

Then, if it is not in an overcharged state or an overdischarged state, it ends.

The above battery protection method has been described with reference to the flowchart shown in the drawings. Although the method is shown and described in a series of blocks for the sake of simplicity, the invention is not limited to the order of the blocks, and some blocks may occur in different order or simultaneously with other blocks than those shown and described herein. Various other branches, flow paths, and blocks may be implemented in order to achieve the same or similar results. In addition, not all illustrated blocks may be required for the implementation of the methods described herein.

While specific embodiments of the present invention have been illustrated and described, the technical spirit of the present invention is not limited to the accompanying drawings and the above description, and various modifications can be made without departing from the spirit of the present invention. It will be apparent to those skilled in the art, and variations of this form will be regarded as belonging to the claims of the present invention without departing from the spirit of the present invention.

Claims (13)

A detector for detecting an overcharge state or an overdischarge state of a battery; A plurality of switches provided in a charging path and a discharge path of the battery; And When the battery is not in an overcharged state or an overdischarged state, the plurality of switches are controlled to enable both the charging and discharging of the battery, and only the charging at the time of overcharging or the charging at the time of overdischarging by the output signal of the detector. And a control unit for controlling the plurality of switches to enable the battery protection device. The method of claim 1, The battery protection device further comprises a plurality of unidirectional elements in the charge path and the discharge path of the battery. The method of claim 2, And the unidirectional element is a diode. The method of claim 1, The plurality of switches, And a second switch provided in the charging path and a second switch provided in the discharge path. The method of claim 4, wherein The control unit, And detecting the overcharge state, by opening the first switch and closing the second switch to control only the discharge. The method of claim 4, wherein The control unit, And when the sensing unit detects an over-discharge state, closes the first switch and opens the second switch to control only charging. The method of claim 1, And a display unit which displays a charging state or a discharging state of the battery. The method of claim 7, wherein The display unit, When the detection unit detects an overcharge state, it indicates that the overcharge state, and if the detection unit detects an over discharge state, the battery protection device, characterized in that indicating the over discharge state. Detecting overcharge or overdischarge of the battery; Controlling the plurality of switches to enable both charging and discharging of the battery when the battery is not in an overcharge state or an overdischarge state; And And controlling the plurality of switches to allow only discharge during overcharging or only charging during overdischarge by the output signal of the sensing unit. The method of claim 9, The controlling of the plurality of switches to enable only discharge when overcharged or only charge when overdischarged by the output signal of the sensing unit includes: And detecting an overcharge state of the battery in the detecting step, controlling the discharge to be possible only by opening the first switch and closing the second switch. The method of claim 9, The controlling of the plurality of switches to enable only discharge when overcharged or only charge when overdischarged by the output signal of the sensing unit includes: When the over-discharge state of the battery is detected in the sensing step, the battery protection method characterized in that the first switch is closed and the second switch is opened so that only charging is possible. The method of claim 9, And displaying the charging state or the discharging state of the battery. The method of claim 12, The displaying step, When the over-charge state is detected in the detecting step, it indicates that the over-charge state, and if the over-discharge state is detected in the detecting step, the battery protection method characterized in that it indicates that the over-discharge state.

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